In this work, the evolution of retained austenite during isothermal bainitic heat
treatment in SAE 52100 steel, 1.01C–1.36Cr–0.32Mn–0.25Si
(wt.%), is investigated with optical microscopy, X-ray diffraction and thermo-magnetic
measurements. A significant amount of austenite is retained
in the material. The dependence of the volume fraction of retained austenite on bainitic
holding time at 503K shows a maximum at 45 min. It has
been demonstrated that the increase of volume
